Shocking allegations that the late princess Diana betrayed Buckingham palace just before her separation from prince Charles. Leaking a confidential royal phone directory, directory to a top newspaper and lama Hasan has our story. Reporter: It was stunning testimony in an already salacious case. Former royal reporter Clive Goodman testifying during Britain's ongoing phone hacking trial, that princess Diana sent him Buckingham palace's confidential contact Numbers. She was fighting for her life. She was frightened she would lose the children. So no trick was too dirty. Reporter: In his explosive evidence, Goodman denied illegal paying for palace documents. Claiming the princess gave him a cop secret Buckingham palace phone book packed with royal contacts and household information to, quote, take on her estranged husband prince Charles in 1992. Diana spilled secrets every day. It was the war of the waless. I don't think Diana would care if someone thought she had taken the Buckingham palace phone directory. It's not like she's taken the crown jewels. Reporter: After all, Charles and Diana's relationship was on the rocks. They separated soon after this event. Goodman alleges that, quote, she felt she was in a very bitter position at the time. She felt she was being swamped by the people close to him and she was looking for an ally to take him on to show the kind of forces ranged against her. He said the contact Numbers helped him write these headline-grabbing stories on the Royals for "News of the world." Goodman is one of seven former journalists for the paper now on trial accused of hacking into their victims' phones to get scoops. They deny the allegations. For "Good morning America," lama Hasan, ABC news, London.

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